1. Technical Field
The present invention relates to ambient noise filtering methods, and particularly to an ambient noise filtering method used in a mobile phone.
2. General Background
With the increased pace of modern life, the ability to communicate anywhere and anytime is important to many people. One result is the increasing use of mobile phones. Mobile phones have enabled individuals to communicate while being in a variety of environments, such as airplanes, cars, restaurants, and other places. Some of these environments are associated with considerable ambient noise that makes it difficult to clearly transmit and receive intelligible speech at an audible level.
As a result, the individuals on a phone conversation may often have to repeat themselves, which is inconvenient, time-consuming, inefficient and costly. Alternatively, they may shout or raise their voice to be heard over the ambient noise, which compromises the privacy of the conversation. A person in a noisy environment may also increase the volume of the mobile phone in order to hear the person who is speaking on the other hand.
Manually adjusting the volume level in response to loud ambient noise is tedious for both the individual at the speaking end and the individual at the listening end. Furthermore, manually increasing volume in response to the ambient noise is undesirable since the volume must be later manually decreased to avoid acutely loud reception when the ambient noise dies down. In addition, if the mobile phone user raises his voice to be heard on the other end of the line, this has the undesirable effect of increasing the ambient noise in the user's environment.
Indeed, within a given environment, the level of the ambient noise may fluctuate, for example, in a car, the ambient noise may vary depending on a number of external factors, such as the amount of traffic, the speed of the car, the output of the car stereo, the engine, the type of road, and other variable factors. In such environment, manually adjusting the volume in response to each instance that the ambient noise increases or decreases is not only tedious but distracting and can be dangerous.
What is needed, therefore, is a mobile phone capable of automatically filtering ambient noise and an ambient noise filtering method used therein.